Electric-switch box



2 SHEETS-SHEET l- INVENTOR F. G. WHITE.

ELECTRIC SWITCH BOX.

APPLICATION FILED ocrT. 23.. 1911.

Patented Jan. 20, 1920.

IIHAYVIIIMIIIIIUIIIv/PII F'. G. WHITE.

ELECTRIC SWITCH BOX.

APPLICATION FILED 0CT23| |911.

2 SHEETS-SHEET 2.

Patented Jan. 20, 1920.

INVENTOR @d 7%@ UNITED STATES PATENT OFFICE.

FRED G. WHITE, 0F KANSAS CITY, MISSOURI, ASSIGNOR 0F CNE-HALF T0 EUGENE W. ENGLE, OF KANSAS CITY, MISSOURI.

ELECTRIC-SVITCH BOX.

Specification of Letters Patent.

Patented Jan. 20, 1920.

Application tiled October 23, 1917. Serial No. 198,076.

To all whom it may concern:

-l'Se it known that I, FRED G. WHITE, a citizen of the United States, residing at Kansas City, in the county of Jackson, State of Missouri, have invented certain new and useful Improvements in Electric- Switch Boxes, of which the following is a full and exact specification.

The present invention relates to lock boxes of the type used for inclosing the cutoff switches of electric wiring systems installed in buildings, etc., and one of the objects in view is to provide a strong box of simple construction adapted to be kept under seal while permitting the renewal of fuses and also safeguarding the electrical connections against any unauthorized tapping of the electric current passing through them.

To this end I provide abox having a locking closure which guards the switch and connections and allows renewal of the fuses, together with a. movable cover member which is obliged to be opened te obtain access to the interior of the box and provided with means operated by the movement of said cover member for automatically opening and closing the switch.

It is also an object to provide a movable cover construction of this character which will also serve to eliminate any possibility of additional wire connections being used for carrying ott' the electric current so long as the cover is closed, this closing of the cover beinr always necessary in order to close the switch Jfor establishing the current.

It is also sought to devise a. durable and economical construction which will be cheap to manufacture and prove efficient for carrying out the desired purposes.

lVith these general objects in view and also minor objects which will appear in the course of the detailed description, he invention will now be described with reference to the accompanying drawings illustrating one form of construction which has been devised for embodving the improvements in practice, after which the features deemed to be novel will be set forth and defined in the appended claims.

In the drawings- Figure l is a longitudinal sectional view of a switch box constructed in accordance .with the present invention, the dotted lines representing different operative positions of the parts F ig. 2 is a plan view of the same with the cover in raised position;

system F 5 is a plan view of the interior locking closure of the box;

Fig. 6 is a side view ot' the same, and

Fig'. 7 is a side view of the box cover.

Referring to 'the drawings in detail, these illustrate the box 8 provided with the usual conduit tubes 10 at its opposite ends for the passage or the conducting wires 12 to the interior of the box, within which is contained the porcelain block 14; secured in place by a plurality o1- bolts 16. The block carries the tuse plugs I8 and also a knife switch comprising` a channel bridge piece 22 connecting the blades 2i which are pivoted to posts 26 and operated to open or close the circuit through the posts 28. For sealing the box the saine is provided with an interior closure member 3G (see Fig. 5) provided with apertures through which to insert the fuse plugs 18, and also with upright side flanges 8e adapted to tit snugly against the side walls of the box. One end ofthe closure member 8O (at what may be termed the front end or' the box) is formed with depending perforated luO's o6 through which to insert a locking pin 38 passing through the sides ot the box, whereby the box may be sealed by a wire Ai() threaded through one end of said pin and an adjacent stud 42, the ends of the wire being secured together by a seal 44e. Toward the rear end of the box the said closure member 3D inclines upwardly over the switch, and the rear edge of said closure member is provided with a pair ot lugs 46 which engage in slots 48 formed in a lguard strip 50, the latter being secured to a flange 52 depending from a top section 53 which overlies the switch operating means housed within the rear end p0rtion of the box. The slots 48 extend through both the guard strip 50 and said depending flange 52 (see Fig. 2).

The box is :further provided with a cover 54 which is required to be closed for the purpose of closing the switch and establishing the current. lThis cover is pivoted by means of a hinge pin 56 at the upper rear corner ofthe box, and is formed with tapered side flanges 58 the edges of which are indicated by the dotted lines in Fig. l, the front end of the cover having a finger-hold 60 whereby the cover may be raised and lowered.

Means is further provided whereby the movement of the cover 54 operates to open and close the switch,.this means comprising a segment 62 pivoted upon a pin 64 extending transversely through the rear end portion of the box and provided with a pair of notches 66 for alternately engaging and retaining the upper and lower margins of the bridge piece 22 of the switch. IThe segment is also formed with an irregular slot 68 within which rides a pin 70 carried by the lower ends of a pair of links 72 straddling said segment, the upper ends of said links being pivoted at 74 to a lug 7 6 depending from a reinforcing strip 7 8 mounted on the outer face of the cover and projecting down therethrough. A slot is formed in the top section 53 for accommodating said lug 76 and the movement of the upper ends of the links 72. A spring 82 carried by the segment 62 serves to maintain the pin 70 in the offset portion 68 of the slot 68 during the swinging movement of said segment as actuated by the cover, the remaining portion of said slot being for the purpose mainly of allowing sufficient movement of the cover to fully-open position.

F rom the foregoing the operation and function of the device will be readily understood. The box 8 is installed in proper working relation to the conduits 10 and the usual meter 84 as illustrated in Fig. 4. So long as the cover 54 is closed it will maintain the switch closed by virtue of the fact thatthe segment 62 is held in the position shown by the full lines in Fig. 1, with the forward notch 66 of the segment engaged with the bridge piece 22 of the switch. Whenever the cover is raised for inspection of the box or renewal of the fuses, the swinging movement of the cover eXerts a pull on the links 72, thereby partially rotating the segment 62, the pin 70 remaining seated in the offset .68 lof the slot 68 until the contact between the switch and the posts 28 has been broken, after which, if the cover is lifted sufficiently, the pinmay pass out of said offset, in opposition to the spring 82, into the elongated portion of said slot to permit the further movement of the cover lwith some additional turning of the segment according to the extent to which the cover is being lifted. The rotation of the segment by any material movement of the cover, suticient to open the switch, will bring the second notch 66 of 'the'segment at least up to or past the lower margin of the channel bridge piece 22 of the switch, thereby effectively maintaining the switch in open or circuit-breaking position. @bviously the switch can not be closed without lowering and closing of the cover, whereupon the .reverse of the action just described takes place, the second or rear notch 66 of the segment engaging and partially rotating the switch and bringing the parts into proper relation for engaging thev other notch of the segment with the top margin of the bridge piece 22 as before, after which the final closing movement of the cover operates through said segment to completely close the switch and also to maintain the same securely locked in closed osition. In this reverse movement the pin O is carried at once to the offset portion 68 of the notch 68 and is snapped back into said offset portion by the spring 82.

It will now be clear that no current can pass through the connections controlled by the switch excepting when the cover 54 is closed, since at all other times the switch is held open. 1n order to make any unauthorized electrical connections to the current conducting elements, such connections would have to be made through or around the closure member 30, to which access can only be had by lifting the cover 54. However, such connections can not be utilized with the cover left open and no current passing, and hence, since it is necessary to close the cover in order to establish the current, any connections led out over the sides of the box would simply be sheared oi'f by the closing of the cover,-all the parts of the box, in cluding the closure member and the cover, being made of moderately heavy sheet steel. Such a shearing action will be facilitated by the tapered form 0f the side iianges of the cover from front to rear, and the slight forward tilt given the upper portion of the front end wall of the boX 8, as illustrated at 86 in Fig. l; and the front end flange 88 of the cover is suitably concaved so as to effect a prolonged shearing engagement with the upper edge of said front wall of the box. The side walls of the boX are securely reinforced from within by the upright flanges 34 projecting up from the sides of the closure member 30. The guard strip 50 prevents the leading of anv connections in from the rear end of the box between the cover and the top section 58, since any such connections would, on closing of the cover, be slieared olf by the action of said guard strip passing out through the slit 90 in the cover, which slit is provided for cooperating to that end with said guard strip. When the cover is closed it will be observed that all access to the interior of the boX by way of the passage between the cover and top section 53 is cut o5 by said guard strip 50, and

the slot 80 is likewise closed up by the cover 130 and its reinforcing strip 78. It is theretore apparent that all tampering with the box for the purpose or" making improper connections with the current coi-iductors is elllectually prevented, it being1 necessary to brealr the seal and remove the closure meA ber SO in order to malte any unauthorized use of the current. No removal of the closure member is necessary, however, for merely replacing or renewing the fuse plugs.

VVhil-e the foregoing represents what is now regarded as the preferred torni of embodiment of the improvements, the right is reserved to all such formal changes or modiications as may fairly fall within the scope oi the appended claims.

IV hat I claim is;

l. A lock box for electric switches, comprising a box hafiffing a movable cover, and provided with a single compartment equipped with fuse plug sockets and with a movable switch element, a locking closure member positioned beneath said cover and over said compartment, said closure member being apertured tor permitting theinsertion of fuse plugs into said sockets, and means operated automatically by the movement of said cover tor opening and closing said switch element.

2. A lock box `for electric switches, comprisinni a box having a movable cover, a movable switch element contained within said box, a swinoing segment having a notched portion for engaging the switch element, and a connection between said segment and cover whereby said segment is actuated by the movement o the cover to open and close said switch element.

3. A lock box for electric switches, comprising a box having a hinged cover, a movable switch element contained within said box, a locking closure member positioned over the switch element and provided with apertures permitting the insertion of fuse plugs, a guard plate carried by the box and extending transversely between said apertures and the hinged end oic said cover, said cover being provided with a slit permitting passage of said guard plate, and means actuated by the movement of said cover for aut0- matically opening and closing said switch element.

L A lock box for electric switches, comprising a box having a hinged cover provided with side edges adapted to cooperate with the sides of the box for producing a shearing action, a movable switch element contained within said box, a locking closure member positioned over the switch element and provided with apertures for permitting the insertion of fuse plugs therethrough, transverse shearing` means located between said cover and closure member and intermediate said apertures and the hinged end of the cover, said shearing` means being operative during the closing movements of the cover, and means actuated by the movement of said cover for automatically opening and closingA said switch element.

5. A lock box for electric switches, comprising a box having a movable cover, a movable switch element contained within said box, and a swinging segment operated by the movements of said cover for opening and closing said switch element and acting to maintain said element locked in either its open or its clos-ed position.

In witness whereof I alix my signature.

FRED G. WHITE. 

